The present invention relates to methods and apparatus for shutting a conduit.
In order to extinguish a burning oil or gas well, it has previously been the practice to apply fire-dousing materials to the upper end of the well pipe at the source of the fire. Such a practice is highly difficult and dangerous due to the intense heat encountered from the flames. Also, some extinguishing techniques result in a clogging of the well pipe, requiring considerable effort to reopen the pipe. It would be desirable to be able to extinguish the fire while remaining at a safe distance from the flames.
It would also be desirable to be able to attach a shut-off valve to other types of fluid pipes such as buried water or natural gas transport pipes for example. In many cases such transport pipes are branched from a main pipe. If a branch line bursts, it may be necessary to close down the entire pipe system, including other branches which have not ruptured. It would be desirable to be able to shut-off only the ruptured branch.